package com.itheima.reggie.filter;

import com.alibaba.fastjson.JSON;
import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Slf4j
@WebFilter("/*")
public class LoginCheckFilter implements Filter {
    //路径匹配器
    private static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        //1. 获取本次请求的URI
        String requestURI = request.getRequestURI();
        log.info("收到拦截请求:{}", requestURI);
        //定义不需要处理的路径
        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**"
        };

        //2. 判断本次请求, 是否需要登录, 才可以访问
        boolean check = check(urls,requestURI);
        //3. 如果不需要，则直接放行
        if(check){
            log.info("本次请求{}不需要处理",requestURI);
            filterChain.doFilter(request,response);
            return;
        }

        //4. 判断登录状态，如果已登录，则直接放行
        if(request.getSession().getAttribute("employee") != null){
            log.info("用户已登录,用户id为:{}",request.getSession().getAttribute("employee"));
            filterChain.doFilter(request,response);
            return;
        }

        log.info("用户未登录");
        //5. 如果未登录, 则返回未登录结果
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;
    }

    /**
     * 检查路径匹配
     * @param urls
     * @param requestURI
     * @return
     */
    private boolean check(String[] urls, String requestURI) {
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if(match){
                return true;
            }
        }
        return false;
    }
}
